Telephone relay or repeater.



PATENTED FEB. 5, 1907.

A. L. PARGBLLE.

TELEPHONE RELAY OR RBPEATBR.

APPLICATION FILED OOT.12,1900.

.of Massachusetts, have ALBERT L. PARCELLE, OF BOSTON, MASSACI-IUSEI"1.S.

TELEPHONE RELAY OR REPEA'F E R.

Specification of Letters Patent.

Patented Feb. 5, 1907.

Application filed October 12, 1900. Serial No. 32.871.

To (1 "171.0112 it may cancer/1,.-

Be it known that I, ALBERT L. Panorama, of Boston, in the county of Snfl'olk and State invented certain how and useful Improvements in Telephone .lle-

lays or Repeaters, of which the following is a specification.

This invention, which relates to apparatus for transmitting electrical impulses, has lor its object the production of a practical telephone relay or repeater by means of which the most minute electrical undulations or waves set in motion by correspmiding soundwaves impinging upon the transmitter in one circuit may be duplicated in another circuit without loss.

In carrying out the invention I place in the receiver or intermediate circuit a conductor of variable conductivity, such as granular carbon, and arrange it'in the field of a magnet controlled by the transn1ittercircuit, so that the current of electricity in the receivercirouit will take the path of the magnetic lines of force, whereby the variation of conductivity of the variable conductor will be in exact accordance with the variation in the strength of the magnet due to the electrical undulationsor impulses in the transmittercircuit. I likewise secure a microphonic effect by confining the granular material and arranging the magnet in such relation thereto that a compression or expansion of the material takes place, according to the elec trical impulses or undulations in the coil which "surrounds a part of the magnet.

On the accompanying drawings 1 have diagrammatically illustrated and in the follow,- ing specification have described a telephone relay or repeater embodying my invention; but it will be borne in-mind that various changes may be made in said relay without departing from the spirit and scope of the invention, that the phraseology which 1 cmploy is for the purpose of description and not of limitation, and that I reserve the right to employ all known electrical and mechanical equivalents for the various parts or features of my inventionwhere substantially the sameresults are accomplished by their employment. Referring to the said drawings, Figure 1 represents diagrammatically a relay embodying my invention. Fig. 2 represents a i-each of which in form of holder for the granular material.

c I 1 1g. .5 represents another embodiment ol the invention.

()n the drawings, (1 indicates a two-part circular or ring-like magnet, the sections of which are indicated, respectively, at a a and the illustrated embodiment of the invention is semicircular in shape. The two sections (1 11'' have abutting ends a a, one of which. is concave, while the other is convex, whereby one section of the magnet may be oscillated relatively to the other section without disturbing the magnetic reluctance at the ends a the sockets serving substantially as a pivot for the end. (1. Between the free ends of the sections a (1 there is a small gap'inwvhich are placed two thin rcsilicnt electrically-conducling disks or diaphragms b I)", separated by a ring N, of material of no or relatively low electrical conductivity. \Vithin the ring is placed a mass of granular material 0, whose electrical cond ucti vity is increased by pressure on its surfa(- --s uch, for instance, as granular carbon.

The section a of the magnet is formed of steel and is permanently magnctidbeing subsequently referred to as the permanent magnet, while the section (1 is of soft iron, (being hereinafter referred to as the electromagnet) and its free end rests upon the disk or diaphragm 1), there being interposed between them, however, a thin sheetdof mica.

A similar sheet is placed between the disk I) On the soft-iron section of the magnet is placed a coil-qnvhich forms a part of the transmitter-circilit,' the latter including the lines c 6 the transmitter c and the source of electrical energy a. The disks or diaphragms I) b and the mass of granular material c are included in an intermediate electrical circuit comprising the lines f f the primary coil f and the source of electrical energy f. The receiving-circuit includes the receiver 9, the lines g g", and the secondary coil 9, the latter being placed in inductive relation to the primary coilf".

The magnet a is small, as is onsistent with 1 the size of the coil 0, and it is arranged up said magnetic lmes of force, according to, the

and the bered, is placed between the disks 1) b) is pass other material of formed of compressed carbon or plumbago or low electrical conductivity. it has us inner edges beveled or rounded, so

that the upper disk or diaphragm rests onlypolarity of the circuit, causing what I term magnetic impulses similar electrical impulses. The variations strength of the magnet or the magnetic impulses all cct a like change in the coi'idnctivity in form to the m of the mass of granular material c. and elec- 1 or '2.) has a coil 71 or 1, placed on the magnettrical impulses or undulations take place in the intermediate circuit ff similar to those in the transmitter-circuit, causing pulses or undulations in the receiver-circuit. Inasmuch as the free end of the magnetsecticn (L2 rests uponthe disk 6, the passage of electrical undulations or waves through the coil 6 in one direction causes the said section to be magnetized and to approach the permanent magnet, whereby the granular carbon is compressed between the end thereof like imcircuits /2V and i.

and the adjacent pole of the magnet-section a, with the consequent increase in condac- V tivity otthesaid material and the passage of similar waves or undulatlons m the. mtermediate circuit. If the electrical waves or impulses traverse the coil in the other direction, the free end of the magnetic section a will be oppositely polarized and move away the poleof the section (1, thereby permitting the disks 1) b to spring apart by their inherent resiliency, whereby the resistance of the granular material is increased.

From this description it will be seen-that from which it may the intensity of th eintermediate circuit (which includes the battery f "l is regulated or varied by the impulses, undulations, or

waves coming over the transmitter-circuit and that by reason of the primary and sec- 1 ondary coilsf" 9 electrical waves or impulses similar to those 111 the intermediate circuit between said poles and being compressible are set up in the receiver-circuit.

It is evident that since the path of the current in the intermediate circuit is the.

same as the path for the magnetic lines of force through the air-gap between the poles of the magnet the conductivity of the. granular material is effected both by the variation in the density of the said material and by the It is also evident that the parts which I have described may be formed and arranged in a number of ways. For instance, in Fig. 2 the rmg within which the granular material is confined (which ring, it will be rememupon a narrow ledge at. is OLHCI edge, and hence more surface is brought into contact between the disk and ring as the disk is pressed down farther and farther.

In Fig. 3 I have shown a relay in which a transmitter and receiver are placed in the two. main circuits. in this instance each of the main circuits (indicated as a uholcby h cared as a whole by j) has two primary induction-coilsj j placed in inductive relation to the secondary coils h? i of the main The electrical impulses in each one of the circuits will be reproduced in the other circuit through the medium of the intermediate circaiit Although in describing the circuit which includes the conductor of variable conduciivity I have termed it fol the sake of clear ness the intermediate circuit, yct otherwise specified I; employ the term re ccivt-r-circuit. in the claims to mean that (iICUit' to which it is desired to transmit the electrical impulses.

Having thus explained the nature of the invention and described a wayot constructing and using the same, although without attempting to set forth all of the forms in be made or all of the modes of its use, I declare that what 1 claim is 1. A relay or rcpeatcr comprising a receivcr-circuit having a confined mass of granular material of variable conductivity, a twopart magnet one section of which is permanent and the O'tl'ltl of which is electrically magnetized, said sections having their poles oppositely'disposed and movable one toward the OtllG-l, said granular material being placed thereby, and a transmitter-circuit connected with-said electrically-magnetized section of said magnet. I

unless 'section (L The intermediate circuit (indi- 2. A relay or repeater comprising a re ceivencircuit haying a confined mass of granular material of variable conductivity, a ringlike magnet formed in two sections with their oles separated to receive the mass of granuar material between them, one of said sections being permanently magnetic; and a transmitter-circuit having otherof said sections.

3. A relay or repeater a coil about the i I i i I20 having a transmit- I ter-circuit, a two-part ring-like magnet, one

section of which is permanently 'magnetic E and the other of which is soft iron, a transnutter-circuit having a coil about said soft-z iron section, a diaphragm in operative relation to a pole of the soft-iron-nm-gnet sec- In testimony whereof I have uflixed-my tion, a confined mass of granular material of signature in presence of two witnesses. variable conductivity placed between the dim ALBERT L PARCELLE phragm and the pole of the per1nanent-n1agi 5 net section, and a receiver-circuit connected I Witnesses:

to the diaphragm and to the mass of granui MARCUS B. MAY, lar material. I C. O. STECHER. 

